Should I repair or replace my water heater?

By Dana Whitlock. Updated October 13, 2026. How we work.

A wet tank decides it for you

Water seeping from the tank body means a new heater. Steel tanks can't be patched, and a leak only grows. If the tank is dry, two numbers decide it: what the repair costs and how many good years the tank has left.

Most water heater repairs are small. Thermocouples, flame sensors, igniters, heating elements, thermostats, drain valves and relief valves all wear out long before the tank, and fixing them on a younger heater is the obvious move. After about 10 years it gets harder. Each repair is buying time on a tank closing in on its expected life.

When repair is the better choice

Repair wins when the tank is sound and the failed part is one of the swappable ones. A gas heater that won't stay lit, an electric heater gone lukewarm, a drip from the drain valve. Classic repair jobs, and none of them says anything about the tank.

• The heater is less than about two thirds of the way through its expected life. For gas tanks, DOE's 2024 analysis uses an average of about 14.5 years; for electric tanks, about 15.1 years.
• The leak is at a fitting, the drain valve or the relief valve. The tank itself is dry.
• No rust in the hot water, no rust streaks on the jacket, and no heavy rumbling from sediment.
• The part is still under the manufacturer's parts warranty.
• The repair costs well under half of the replacement figure shown above.

When replacement is the better choice

Replacement wins when the tank is failing, or when the repair is expensive next to how long the heater will last. A new gas control valve or a second element on a heater already past its average life often goes into a tank that leaks a year or two later.

• Water is coming from the tank body, or the bottom of the tank is rusting.
• Hot water comes out rusty while cold water runs clear.
• The tank is at or beyond about 12 to 15 years and needs a major part.
• This is the second or third repair in a short span.
• The heater no longer keeps up with your household, and you'd want a different size or type anyway.

Working through the numbers

Cost per remaining year is the cleanest test. Divide the repair cost by the years you expect the old heater to keep working. Divide the replacement cost above by the years a new heater should last. Lower number, better buy.

Say your gas heater is 8 years old and needs a new gas control, quoted at about 15 percent of the replacement figure for your area. The tank is dry and quiet, so another 5 or 6 years is a reasonable expectation. Fifteen percent over 5 years is about 3 percent of a new heater's cost per year. A new heater spread over about 14 years costs a little over 7 percent per year. Repair costs less than half as much per year. Fix it.

Same repair, 14-year-old tank, some sediment noise. You can't count on more than a year or two. Fifteen percent over 1.5 years is about 10 percent per year, already above the 7 percent a new heater costs. Replace, and skip the emergency version of this job when the tank lets go in the middle of a weeknight.

The calculator on this page does the same arithmetic with your actual repair quote, age and local replacement estimate.

The 50 percent rule

Plenty of people use a simpler shortcut: if a repair costs more than about half the price of a new heater, replace. Nobody enforces it. It works well for old heaters and badly for young ones. Half the price of a new heater is a lot to sink into a 13-year-old tank. On a 3-year-old heater with a failed control board, partly under warranty, it can still be reasonable. Use the rule as a first pass and the cost-per-year math to settle it.

What changes the call

Age against typical life comes first. DOE's figures are averages: about 14.5 years for gas tanks, about 15.1 for electric, and about 20 years assumed for gas tankless units. Builder and inspector charts are gloomier, putting tanks anywhere from 6 to 12 years. Hard water and high water pressure push real-world life toward the low end.

Warranty status catches people by surprise. Tank warranties often run longer than parts warranties, and some brands, such as A.O. Smith, let you check coverage online by serial number. A covered part can turn an expensive repair into a cheap one. Labor is often excluded, so ask.

Efficiency counts for less with water heaters than with heating systems, but it adds up if you change types. A heat pump water heater uses far less electricity than a standard electric tank, and DOE's 2024 water heater rule is built around heat pump technology for most electric tanks. An aging electric tank is a natural moment to switch technologies instead of buying the same thing again.

Code and installation changes can tip things too. A replacement may need a thermal expansion tank, updated venting, seismic straps or a drain pan, depending on local code. They raise the cost of replacing without changing the age math.

Safety overrides everything. If you smell gas, leave the house and call the gas utility from outside. Scorch marks near the burner, a vent pipe that has slipped loose, or a relief valve that discharges often all need a licensed plumber before you decide anything.

Before you pay for a big repair

Read the serial number to confirm the heater's real age, since install date and manufacture date can differ. Ask the plumber exactly where any leak is coming from. Ask whether the part is under warranty. And get the replacement price on the same visit, so both numbers sit side by side and nobody is deciding while standing in a puddle.